04 Try it yourself Interactive

One link, two messages, three ways to share it

Same laptop, same server, one link between them. Asha’s laptop has HELLO to send, five characters. The server has a two-character status message OK to send back, and it has had it ready since before the run started — it is not a reply, so it is not waiting for anything. Time runs left to right in slots, one character per slot. Run the same exchange under all three transmission modes and watch which direction is allowed to carry data in each slot. Nothing plays on its own: Next, Back and Reset, or the arrow keys.

Simplex
one channel · direction fixed
Each cell is one time slot on one direction of the link. Indigo = carrying a character now. Green = already delivered. Amber = the slot is spent turning the line around and carries nothing. Dashed grey = this direction does not exist in this mode.
Press Next to begin. Each press advances the run by one slot.


      

        
Slot–

        
Channels–

        
Characters delivered0 / 7

        
Still waiting7

      


      

      

        
        
        
        step 0 / 0